National/International practice guidelines always give me a bit of a dilemma. On the one hand I feel that I really should read them all….., but on the other hand they are usually interminably long and written in a rather dry style. I suppose that this is inevitable. When discussing the management of ST elevation myocardial infarction we cannot expect comedy, but 500+ pages of anything struggles to retain my attention.
Anyway, enough moaning. The management of STEMI is an important part of our practice so this guideline from the American College of Cardiology/American Heart Association is worthy of a look…., not the full 500+ pages though. I think we can confine ourselves to the executive summary.
Most of the guideline is focused on the in-patient management of STEMI. There is a clear focus on getting patients to a centre that can perform PCI (Percutaneous Coronory Intervention) if at all possible. The target times for getting the patient from first medical contact to PCI are 90 minutes if the patient is in the same hospital and 120 minutes if the patient is in a non-PCI capable facility. The upshot of this is that thrombolysis is not dead yet. There are many parts of the world where the transfer time target of 120 minutes to PCI will be unachievable, so there are still recommendations for thrombolysis, but again there is a focus on post thrombolysis PCI for the majority of patients, and in particular for those with thrombolysis failure and/or ongoing problems.
I have rejigged their triage diagram into something a bit more EM focused.
So, that’s the triage element which with PCI being a focus is the main function of the ED. Many other aspects of care such as the use of aspiring, clopidogrel, pragruel etc. are unchanged from our current practice so little new information.
I have had a look through to see if there are any elements that might change my practice in ED and I think I have found 3 areas where the guidance might help in some of the difficult conversations we have had in recent years.
Firstly, post cardiac arrest (with ECG changes) there is a clear indication for PCI. This is something we have encouraged locally. In practice this means that our/your systems need to be capable of the rapid transfer of intubated patients to the cath lab (as many patients post CA will be critical care patients). So, a question for your practice – how slick are your ED – Cath Lab transfers for the intubated critical care patient?
Immediate angiography and PCI when indicated should be performed in resuscitated out-of-hospital cardiac arrest patients whose initial ECG shows STEMI.
Secondly, in the group of patients where PCI is not possible on geographical grounds the use of thrombolytics is advocated for STEMI. What is a bit surprising is the comments around the diagnosis of posterior MI through the use of reciprocal leads. Personally I’m a big advocate of posterior leads, but at least there is a recognition of the need for intervention for patients with posterior MI (they were excluded from many trials of thrombolysis). There is also the clear recommendation that all patients need to be considered for PCI post thrombolysis. A challenge for those in remote areas!
In the absence of contraindications and when PCI is not available, fibrinolytic therapy is reasonable for patients with STEMI if there is clinical and/or electrocardiographic evidence of ongoing ischemia within 12 to 24 hours of symptom onset and a large area of myocardium at risk or hemodynamic instability.
Class III: Harm
Fibrinolytic therapy should not be administered to patients with ST depression except when a true posterior (inferobasal) MI is suspected or when associated with ST elevation in lead aVR.
Immediate transfer to a PCI-capable hospital for coronary angiography is recommended for suitable patients with STEMI who develop cardiogenic shock or acute severe HF, irrespective of the time delay from MI onset .
Urgent transfer to a PCI-capable hospital for coronary angiography is reasonable for patients with STEMI who demonstrate evidence of failed reperfusion or reocclusion after fibrinolytic therapy.
Transfer to a PCI-capable hospital for coronary angiography is reasonable for patients with STEMI who have received fibrinolytic therapy even when hemodynamically stable§and with clinical evidence of successful reperfusion. Angiography can be performed as soon as logistically feasible at the receiving hospital, and ideally within 24 hours, but should not be performed within the first 2 to 3 hours after administration of fibrinolytic therapy.
Thirdly, the management of cardiogenic shock post STEMI has a number of recommendations. Early PCI is still advocated strongly, and again this takes me back to the need to ensure smooth and safe ED – Cath Lab transfers for critically ill patients. For those with cardiogenic shock the use of intra-aortic balloon pumps is still advocated if pharmacological therapy fails. The nature of pharmacological intervention is not defined in this exec summary.
Emergency revascularization with either PCI or CABG is recommended in suitable patients with cardiogenic shock due to pump failure after STEMI irrespective of the time delay from MI onset
In the absence of contraindications, fibrinolytic therapy should be administered to patients with STEMI and cardiogenic shock who are unsuitable candidates for either PCI or CABG
The use of intra-aortic balloon pump counterpulsation can be useful for patients with cardiogenic shock after STEMI who do not quickly stabilize with pharmacological therapy
So, in summary there is little new here for my practice, a few points that may help the complex discussions about patient suitability for PCI that sometimes crop up. A useful clarification for the post cardiac arrest and cardiogenic shock patient. Practically the big message is to look at our systems for the safe transfer of critically ill patients from the ED to the cath lab.
5 thoughts on “New STEMI Guidelines. St.Emlyn’s”
Thanks a lot, Simon – a very valuable post. Did you notice the ECG criteria for diagnosing STEMI? They are similar to those specified in the 2012 ESC guideline but they are different to what we’ve traditionally been used to. In the UK, we’ve generally held that STEMI can be diagnosed in the appropriate clinical context when there is >=2mm ST elevation in two contiguous chest leads or >=1mm ST elevation in two contiguous limb leads.
Since publication of a paper in around 2004 looking at the gender and age specific differences, the criteria have changed – but I’m not sure we all know about it…
The AHA/ACC guideline states that we can diagnose STEMI (in the absence of LBBB and LVH) if there is >=2mm ST elevation in V2-3 in men or >=1.5mm in women; or of there is >=1mm ST elevation in other leads.
The ESC guideline actually goes even further to identify the age-specific differences in V2-3. So, we can diagnose STEMI if there is:
* >=2.5mm ST elevation in V2-3 if male and <40 years old
* >=2mm ST elevation in V2-3 if male and >40 years old
* >=1.5mm ST elevation in V2-3 if female
* >=1mm ST elevation in 2 contiguous leads elsewhere, regardless of age and gender
What’s more, the guideline states that we should measure this at the J point. Evidence for this may still be lacking – but that’s what the guideline says!
Finally and importantly, the ESC guideline goes on to say that “typically” these changes occur in STEMI. I.e. the ESC guideline recognises that some cases of STEMI won’t actually meet those objective criteria.
This seems to acknowledge that we often diagnose STEMI in the absence of those criteria – e.g. <1mm inferior ST elevation with low voltage QRS complexes, high lateral STEMI with ST elevation in aVL, etc. The ESC guideline also highlights the importance of ST elevation in aVR and posterior STEMI, when the criteria stated may not be met.
I think that info is still not ‘out there’ Rick. We’ve been looking at ECG criteria for a long time so hopefully have better familiarity, but I wonder if this has been as widely adopted as we would wish?
What do you reckon?
There is much that is wrong with these guidelines.
First on aVR:
I) The following statement is slightly misquoted and is also erroneous in the STEMI document:
Class III: Harm
Fibrinolytic therapy should not be administered to patients with ST depression except …. when associated with ST elevation in lead aVR.
This is the actual quote: “Multilead ST depression with coexistent ST elevation in lead aVR has been described in patients with left main or proximal left anterior descending
2) ST elevation in aVR has been erroneously associated with left main occlusion. This is a gross misinterpretation of the literature. I have thoroughly reviewed the lit in this article:
Unless there is ST elevation elsewhere in addition, ST elevation in aVR is associated with LM insufficiency, NOT occlusion.
Suffice it to say that, unless there is anterior STEMI evident on the ECG, ST elevation in aVR is reciprocal to widespread ST depression (lateral and inferior ST depression) which is NOT amenable to thrombolytic therapy. It certainly may benefit from PCI, but the evidence is AGAINST thrombolytics for this. The reference that the ACC/AHA document gives says NOTHING about aVR, and, if it did, it would be, as so much of the lit on this is, erroneous.
I wish I could post my entire piece on aVR here, but I it might violate copyright, though I actually doubt it.
Second, on ST elevation criteria:
Also, I should add that I have evaluated every ST elevation criteria for anterior STEMI and they perform terribly (accuracy around 60% for all of them). See Table 4 in this paper on early repol vs. anterior STEMI: http://download.journals.elsevierhealth.com/pdfs/journals/0196-0644/PIIS0196064412001606.pdf. No other study has evaluated ST elevation criteria using angiography. All previous ones were based on biomarkers, and are very old and poorly done studies.
Steve Smith of Dr. Smith’s ECG Blog
Thanks for this post.
Quick question/comment regarding triage diagram: Did you mean to write “STEMI patient suitable for repercussion” (in which case I’m most likely having yet another thick moment), or was that meant to read reperfusion?
See you Thursday at Joe Lex’s talk (coming with one of your SpRs – KP)
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